JP4745369B2 - Linear motor - Google Patents

Description

  The present invention relates to a linear motor in which a mover linearly reciprocates along a stator.

  2. Description of the Related Art Conventionally, a linear motor in which a mover moves back and forth linearly along a stator is known.

  The linear motor mainly includes a stator that is fixed in a predetermined position in the linear motor, and a mover that moves on the guide member along the stator. One of the mover and the stator is provided with a permanent magnet, and the other is provided with an armature. Then, by supplying a current to the armature, a predetermined magnetic flux is generated around the coil constituting the armature to obtain an electromagnet. The mover receives an attractive force and a repulsive force between the permanent magnet and the electromagnet, and moves along the stator (see Patent Document 1).

The armature is driven efficiently by supplying a predetermined current corresponding to the positional relationship between the electromagnet and the permanent magnet to the armature. In particular, at the beginning of use, the electrical angle of the current that operates the mover is specified. Specifically, as shown in FIG. 6, by moving the mover 12 slightly in the direction A and the direction B with reference to the position of the mover 12 when the power is turned on, the electromagnet and the permanent magnet are moved. The electrical angle of the current according to the positional relationship is specified.
Japanese Patent Laid-Open No. 2002-247886

  When the process for specifying the electrical angle is performed as described above, if the mover 12 is located at the end of the movable range, the mover 12 is only in one direction A or B. Can not be moved. In order to cope with such a situation, an error processing system as shown in FIG. 7 is introduced. Specifically, first, an electrical angle of +90 degrees and an electrical angle of −90 degrees are given to the armature e on the basis of the position of the movable element 12 when the power is turned on (steps S1 and S2), and the armature e is movable. The amount of movement of the child 12 is determined (step 3). If the determination of the amount of movement of the mover 12 is not completed successfully (step S4), after the retry as shown in FIG. 7 is repeated a predetermined number of times (step S41, step S42), the linear motor Final error processing such as stopping the operation is executed (step S43). That is, even if such an error processing system is introduced, much time is spent before the final error processing (step S43) is executed, rather than specifying the electrical angle. The discovery of is greatly delayed.

  Further, in the technique of Patent Document 1, a pair of limit switches is provided between stoppers arranged at both ends of the movable range of the mover, and when the mover reaches the position of the limit switch, the limit switch transmits a signal. The mover is controlled to be prohibited from moving to the end of the movable range. However, in this case, since a pair of limit switches are provided to control the driving of the mover, a complicated system is required in addition to an increase in the number of parts.

  The present invention has been made in view of the above-described conventional problems. When the mover is located at the end of the movable range, the magnetic pole estimation can be performed without requiring a complicated system. It aims at providing the linear motor which can move a needle | mover to a position.

The linear motor of the present invention includes a stator, a mover that linearly reciprocates along the stator, an armature provided in one of the stator or the mover, and a permanent magnet provided in the other. And a stopper positioned at the end of the movable range of the mover, and when a current is supplied to the armature when the power is turned on, a temporary current for operating the mover A linear motor in which a magnetic pole estimation operation is performed to move the mover by a predetermined movement amount capable of specifying an electrical angle, and the armature includes a magnetic body at an end thereof, and the magnetic body, The stopper and the permanent magnet receive a magnetic force acting between the permanent magnet and the magnetic body when the mover contacts the stopper with the supply of current to the armature cut off. The movable element The positional relationship is determined so as to move to a position separated from the pad by a predetermined distance, and the position that is separated from the stopper by the predetermined distance is displaced by the predetermined movement amount in the magnetic pole estimation operation. It has a feature in that it is a position that allows it to be performed.
The linear motor of the present invention includes a stator, a mover that linearly reciprocates along the stator, an armature provided in one of the stator or the mover, and a permanent provided in the other. A linear motor having a magnet and stoppers positioned at both ends of the movable range of the mover, wherein the permanent magnet has an armature arrangement length in the same direction as the arrangement length of the mover in the reciprocating direction. provided longer than is said the armature is provided with a magnetic body at both end portions in the arrangement length direction, these magnetic, the stopper and the permanent magnets, the mover relative to the stopper Are in contact with each other, the magnetic body on one side of each of the magnetic bodies is positioned outside the both ends of the permanent magnets and inside the stoppers in the arrangement length direction. Force is characterized in that the mutual positional relationship is defined so as to be located in a position spanning the magnetic of the one side.

According to these inventions, even mover temporary is interrupted the power supply to the armature at which contact with the stopper, by a magnetic force, the movable element is pulled back in a direction away from the stopper. Therefore, when the mover is positioned at the end of the movable range, the mover can be moved to a position where the magnetic pole can be estimated without requiring a complicated system.

In each of the above near motors, the magnetic body is preferably a sub-teeth.

  According to this invention, since the magnetic body is a sub-tooth, the mover can be moved to a position where magnetic pole estimation can be performed without adding a part and without requiring a complicated system. it can.

The armature is connected to a control unit, and the control unit separates the mover from the stopper when the mover contacts the stopper and the current supply to the armature is interrupted. In a stopped state, the first means for specifying an electrical angle of a provisional current for operating the mover, and the mover is moved based on the electrical angle of the current specified by the first means. Second means for providing an initial value of an electrical angle of a current specified in advance according to a positional relationship between the armature and the permanent magnet when the mover is positioned at a predetermined position, It is preferable that the electrical angle of the current corresponding to the positional relationship between the armature and the permanent magnet is set stepwise by the one means and the second means.

  According to this invention, the electrical angle of the current is set stepwise by the first means and the second means. That is, by setting the electrical angle of the provisional current by the first means, the mover can be operated for the time being, and the provisional set by the first means by the second means. The mover is moved to a predetermined position based on the electrical angle of the current, and the initial value of the electrical angle of the current specified in advance is given, and an appropriate current according to the positional relationship between the armature and the permanent magnet is supplied. As a result, the mover can be operated very efficiently.

  According to the present invention, when the mover is located at the end of the movable range, the mover can be moved to a position where magnetic pole estimation can be performed without requiring a complicated system.

  Below, the linear motor of this Embodiment is demonstrated in detail using drawing.

(Embodiment 1)
1 and 2 are conceptual diagrams for explaining a linear motor. FIG. 1 shows a state in which the mover 12 is in a position in contact with the stopper 11, and FIG. 2 shows a state in which the sub teeth e 13 provided at the end of the mover 12 generate a magnetic force by the permanent magnet ma of the stator 13. The state which received and moved in the direction away from the stopper 11 is shown. Below, the direction parallel to the moving direction of the needle | mover 12 is demonstrated as a X direction, and the direction orthogonal to a X direction is demonstrated as a Y direction.

  As shown in FIGS. 1 and 2, the linear motor according to the first embodiment has a stator 13, a permanent magnet ma provided on the stator 13, and a movable body that linearly reciprocates along the stator 13. A child 12, an armature e provided in the mover 12, and a pair of stoppers 11 positioned at the end of the movable range of the mover 12 are provided. In addition, the linear motor is provided with a linear guide 14 for guiding the mover 12 and a control unit 15 for controlling the current supplied to the armature e. The stator 13, the permanent magnet ma, the mover 12, the armature e, the stopper, and the linear guide 14 are integrally accommodated and held by a frame member 16. Since the frame member 16 is not particularly limited in the present embodiment, the description thereof is omitted here.

  The stator 13 includes a support member 13a that is a linear long body. The support member 13a is fixed at a predetermined position on the frame member 16 of the linear motor. A permanent magnet ma is disposed on the support member 13a of the stator 13 along the longitudinal direction.

  The permanent magnet ma is attached to the support member 13a of the stator 13 so that the N pole and the S pole appear alternately at a predetermined interval. Moreover, in this Embodiment, the range in which the permanent magnet ma is provided is defined so that it may become a specific range. Specifically, the permanent magnet ma is disposed so as to be shorter than the distance between the pair of stoppers 11.

  The mover 12 has a support member 12a. The support member 12a is for attaching a member for supporting the armature e at a predetermined position in the linear motor and transmitting the power of the mover 12 to the outside. The mover 12 is arranged so that its moving direction is parallel to the longitudinal direction of the stator 13.

  The armature e includes a core e10 and a coil e20.

  The core e10 is a member formed of a magnetic material such as iron, and includes a common part e11, a main teeth e12, and a sub teeth e13. The common part e11 has a substantially rectangular parallelepiped shape, and is fixed to the support member 12a of the movable element 12 with its longitudinal direction being substantially parallel to the moving direction of the movable element 12. A plurality of main teeth e12 are formed in parallel so as to protrude from the common portion e11 in a direction orthogonal to the moving direction of the mover 12. A pair of sub teeth e13 are provided at the end of the mover 12 in the moving direction so as to sandwich the main teeth e12. The sub teeth e13 are for supplementing the magnetic flux formation at both ends of the mover 12 when the motor is driven. In the present embodiment, the movable element 12 is moved from the predetermined position by a predetermined distance from the magnetic force acting between the sub teeth e13 and the permanent magnet ma in a state where the supply of current to the armature e is cut off. Get the driving force to make it happen.

  The coil e20 is a bobbin around which a conducting wire is wound. A plurality of coils e20 are attached to the main teeth e12 so as to be arranged in parallel along the moving direction of the mover 12. Each coil e20 is mounted such that the protruding direction of the main teeth e12 from the common portion e11 is substantially orthogonal to the winding direction of the conducting wire of the coil e20.

  The armature e is supplied with a current of any one of the u-phase, v-phase, and w-phase with different phases to each coil e20, so that a predetermined magnetic flux is generated around each coil e20. An electromagnet is obtained. Then, the sub teeth e13 are magnetized by the electromagnet, so that the magnetic fluxes at both ends of the mover 12 are supplemented. The armature e is installed so as to face the permanent magnet ma attached to the stator 13 with respect to the mover 12. When a predetermined current is supplied to the armature e, the mover 12 is applied to the stator 13 by receiving the magnetic attractive force / repulsive force that interacts between the obtained electromagnet and the permanent magnet ma. Promote along.

  The stoppers 11 are members provided at both ends of the movable range of the mover 12. The stopper 11 plays a role of stopping the mover 12 from moving out of a predetermined range.

  Here, the positional relationship between the stopper 11 and the end portion ma1 of the permanent magnet ma will be described. The permanent magnet ma attached to the stator 13 is formed from the stopper 11 to a position separated by a predetermined area ar1. This area ar1 is an area set as a range in which the magnetism at the end of the permanent magnet ma sufficiently covers the magnetic body located on the area ar1.

  In particular, in the present embodiment, the sub-teeth e13 attached to the end of the mover 12 contacts the stopper 11 in a state where the mover 12 is positioned at the end of the movable range. That is, as shown in FIG. 1, since the area ar1 is secured in the X direction between the stopper 11 and the end portion ma1 of the permanent magnet ma, the sub-tooth e13 is located in the area ar1. become. Since the sub teeth e13 are made of a magnetic material, if the armature e is not functioning as an electromagnet, the sub teeth e13 are attracted by the magnetism of the end ma1 of the permanent magnet ma.

  The linear guide 14 serves to guide the mover 12 in a state where the distance in the Y direction between the mover 12 and the stator 13, that is, the distance between the armature e and the permanent magnet ma is maintained at a predetermined interval. Is responsible. Specifically, the linear guide 14 has a long linear shape, and is positioned between the pair of stoppers 11 with both ends directed toward the stoppers 11 and in a posture substantially parallel to the support member 13 a of the stator 13. It is installed on the member 16. The support member 12a of the mover 12 is engaged with the linear guide 14 so as to be slidable in the longitudinal direction.

  The control unit 15 detects the position of the mover 12 by a detection unit (not shown), and based on the detected position information of the mover 12, the armature e provided in the mover 12 has a permanent magnet ma and an armature. An appropriate current corresponding to the positional relationship with e is supplied. Thereby, the needle | mover 12 is controlled efficiently. Further, the control unit 15 performs magnetic pole estimation for specifying the phase of the current to operate the mover 12 for the time being when the power to the linear motor is turned on. Specifically, current is supplied to the armature e in the plus direction and the minus direction, and the behavior (movement direction) of the mover 12 in each case is detected. Based on the behavior of the mover 12, the phase of the current for operating the mover 12 is roughly specified. Therefore, when the power is turned on, the mover 12 needs to be positioned away from the stopper 11 by a distance necessary for estimating the magnetic pole.

  Here, the case where the needle | mover 12 exists in the position contact | abutted to the stopper 11 is demonstrated. FIG. 3 is an enlarged view of a part of FIG. 1, and is a diagram for explaining the force generated between the end ma1 of the permanent magnet ma and the sub teeth e13 provided at the end of the mover 12. is there.

  As shown in FIG. 3, in a state where the movable element 12 is in contact with the stopper 11, the stopper 11, the end of the permanent magnet ma and the sub teeth e <b> 13 are arranged in the X direction in FIG. The sub teeth e13 are in a positional relationship with the part ma1.

  When the supply of current to the armature e is cut off and the mover 12 is in a position in contact with the stopper 11, as shown in FIG. 3, the end ma1 of the permanent magnet ma and the sub teeth e13 In between, the magnetic force F is acting. In the linear motor according to the present embodiment, the force Fx, which is a component force of the magnetic force F and is parallel to the moving direction of the mover 12 in a state where the mover 12 is in contact with the stopper 11, To exceed the static friction force with the linear guide 14 (the product of the static friction coefficient between the linear guide 14 and the support member 12a of the mover 12 and the load of the member attached to the mover 12 and the mover 12). Is set. Therefore, the mover 12 is attracted to the end portion ma1 of the permanent magnet ma and naturally moves from the stopper 11 to the vicinity of the end portion of the permanent magnet ma (see FIG. 2).

  Therefore, when the power of the linear motor is turned on, the mover 12 is always located at a position away from the stopper 11 by a predetermined distance. The current supplied to the armature e includes a first means 15a provided in the control unit 15 for specifying an electrical angle of a current for operating the mover 12 when the linear motor is driven, and the mover. 12 is moved to a predetermined position and adjusted in a stepwise manner by the second means 15b for giving an initial value of the electrical angle of the current specified at the time of design. Here, the electrical angle means a phase expressed by assuming that one period of the signal sine wave is 360 degrees.

  Specifically, when the electrical angle of the current is specified by the first means 15a, first, the current is supplied to the armature e so that the electrical angle changes by +90 degrees, and the mover from the position when the power is turned on is first supplied. 12 behaviors (movement direction and movement amount) are grasped. Next, the mover 12 is returned to the position when the power is turned on, and an electric current is supplied to the armature e so that the electrical angle changes by −90 degrees, and the behavior (movement direction and movement amount) of the mover 12 is grasped. . In this way, by grasping the behavior (movement direction and movement amount) of the mover 12 when a predetermined electrical angle is given to the armature e, a provisional for operating the mover 12 for the time being is provided. The electrical angle of the current is specified (see FIG. 7, step S1, step S2, and step S3). In particular, in this embodiment, since the power of the linear motor is always turned on in a state where the movable element 12 is at a position away from the stopper 11, the movable element 12 is in contact with the stopper 11. There is no problem that the mover 12 cannot be moved in any one direction and the provisional current electrical angle cannot be specified. Therefore, even if an error processing system as shown in FIG. 7 is introduced, execution of error processing due to the contact of the movable element 12 with the stopper 11 is avoided.

  When the second means 15b gives the initial value of the electrical angle of the current, first, the mover 12 is moved based on the temporary electrical angle of the current specified in the first stage. When the mover 12 is positioned at a predetermined position in the movable range, an initial value of the electrical angle of the current specified in advance in the design stage is given. Such control for giving the initial value of the electrical angle of the current in the second stage is performed by a linear scale L fixed to one of the mover 12 or the stator 13 (fixed to the frame member 16 in FIGS. 1 to 3). The origin signal information L1 recorded in (1) is read by the sensor S fixed to the other of the movable element 12 or the stationary element 13 (fixed to the movable element 12 in FIGS. 1 to 3).

  Thus, an appropriate current corresponding to the positional relationship between the electromagnet and the permanent magnet ma is supplied to the armature e, and the mover 12 is driven extremely efficiently.

  According to the above embodiment, the magnetic force acting between the permanent magnet ma and the sub teeth e13 when the mover 12 comes into contact with the stopper 11 with the supply of current to the armature e cut off. In response, the positional relationship of the end portions of the sub teeth e13, the stopper 11 and the permanent magnet ma is specified so that the mover 12 moves to a position away from the stopper 11 by a predetermined distance. In other words, even if the armature e is de-energized when the mover 12 contacts the stopper 11, or the armature e is de-energized, the mover 12 is manually attached to the stopper 11. Even if it is moved to the contact position, the mover 12 is pulled back in the direction away from the stopper by the magnetic force. Therefore, when the mover 12 is located at the end of the movable range, the mover 12 can be moved to a position where magnetic pole estimation can be performed without requiring a complicated system.

  Further, since the magnetic body is the sub teeth e13, the mover 12 can be moved to a position where the magnetic pole estimation can be performed without adding a part and without requiring a complicated system.

  In the above embodiment, the armature e is provided in the mover 12 and the permanent magnet ma is provided in the stator 13. However, the present invention is not limited to this. FIG. 4 is a conceptual diagram for explaining another form of the linear motor, and shows a state in which the mover is in a position in contact with the stopper. FIG. 5 shows that the mover 12 provided with the permanent magnet ma receives the attraction force generated between the mover 12 provided at the end of the stator 13 and the stopper 11 in the linear motor shown in FIG. The state moved in the direction is shown. For example, as shown in FIGS. 4 and 5, the permanent magnet ma is provided in the mover 12, and the armature e is provided in the stator 13, and the armature e provided in the stator 13. In a state in which the energization of the armature e is stopped, the armature 12 is moved from the stopper 11 by the magnetic attraction force generated between the end ma1 of the permanent magnet ma provided on the armature 12 and the sub teeth e13b of the armature e. The form pulled back in the direction away may be sufficient. In this case, the mover 12 is moved by the magnetic force generated between the permanent magnet ma1 provided at the end opposite to the side in contact with the stopper 11a and the sub teeth e13b of the armature e provided on the stator 13. It is attracted and moves away from the stopper 11a.

It is a conceptual diagram for demonstrating a linear motor, and the state which exists in the position which the needle | mover contact | abutted to the stopper is shown. It is a conceptual diagram for demonstrating a linear motor, The sub teeth provided in the edge part of a needle | mover receive the magnetic force by the permanent magnet of a stator, and show the state which moved to the direction away from a stopper. FIG. 2 is an enlarged view of a part of FIG. 1 and is a view for explaining a force generated between an end portion of a permanent magnet and a sub-tooth provided at an end portion of a mover. It is a conceptual diagram for demonstrating the other form of a linear motor, and the state which exists in the position which the needle | mover contact | abutted to the stopper is shown. It is a conceptual diagram for explaining another form of the linear motor, and the mover provided with the permanent magnet receives the magnetic force generated between the sub teeth provided at the end of the stator and moves away from the stopper. The state moved to is shown. It is a conceptual diagram for demonstrating a linear motor, and is a figure for demonstrating the movement of the needle | mover in the case of the magnetic pole estimation performed at the time of the drive of a linear motor. It is a flowchart for demonstrating an error processing system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Stopper 12 Movable element 13 Stator 15 Control part 15a 1st means 15b 2nd means e Armature e13 Sub teeth (magnetic body)
ma permanent magnet

Claims (4)

A stator, a mover that reciprocates linearly along the stator, an armature provided in one of the stator or the mover, a permanent magnet provided in the other, and a movable range of the mover A temporary electrical angle for operating the mover by supplying a current to the armature when the power is turned on. A linear motor that performs a magnetic pole estimation operation for moving the mover by a predetermined amount of movement,
The armature includes a magnetic body at an end thereof,
The magnetic body, the stopper, and the permanent magnet act between the permanent magnet and the magnetic body when the mover contacts the stopper with the supply of current to the armature cut off. The positional relationship is determined so that the mover moves to a position away from the stopper by a predetermined distance,
The linear motor characterized in that the position away from the stopper by the predetermined distance is a position that allows the mover to be displaced by the predetermined movement amount in the magnetic pole estimation operation. A stator, a mover that reciprocates linearly along the stator, an armature provided in one of the stator or the mover, a permanent magnet provided in the other, and a movable range of the mover A linear motor having stoppers located at both ends of the
The permanent magnet is provided such that the arrangement length in the reciprocating direction of the mover is longer than the arrangement length of the armature in the same direction,
Wherein the armature is provided with a magnetic body at both end portions in the arrangement length direction,
The magnetic body, the stopper, and the permanent magnet are configured such that one of the magnetic bodies has both ends of the permanent magnet in the arrangement length direction in a state where the movable element is in contact with the stopper. The linear motor is characterized in that the positional relationship is determined so that the magnetic force of the permanent magnet is located at a position that extends to the magnetic body on the one side and further to the outside than both stoppers. .   The linear motor according to claim 1, wherein the magnetic body is a sub-tooth. The armature is connected to a control unit,
The control unit
Temporary operation for operating the mover in a state where the mover comes in contact with the stopper and the current supply to the armature is cut off so that the mover is separated from the stopper and stopped. A first means for specifying the electrical angle of the current;
The mover is moved based on the electrical angle of the current specified by the first means, and when the mover is positioned at a predetermined position, the mover is preliminarily set according to the positional relationship between the armature and the permanent magnet. A second means for providing an initial value of the electrical angle of the specified current,
4. The electrical angle of the current corresponding to the positional relationship between the armature and the permanent magnet is set stepwise by the first means and the second means. The linear motor described in the section.

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